spring-projects
DefaultRelyingPartyRegistrationResolver should provide the end user to resolve URL with custom URL templates
Expected Behavior
In DefaultRelyingPartyRegistrationResolver class, there is a private static method resolve() method that is used to resolve URL strings defined in the relying party registration information containing variables, such as {baseHost}, {baseUrl}, etc.
We can enhance this ability by letting the user provide their own HashMap<String> data that can be passed to the UriComponentsBuilder and resolve custom URL template variables the end users use.
https://github.com/spring-projects/spring-security/blob/f82e15d5b65734c64856ec955e82f689bf18fe1f/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/DefaultRelyingPartyRegistrationResolver.java#L87
Current Behavior
In DefaultRelyingPartyRegistrationResolver class, this private static method resolve() method uses the default URL template variables available in the RelyingPartyRegistrationPlaceholderResolvers class. However, if the user needs to do something else with it and provide a different URL component each time, they need to modify the file many times during the ongoing development process.
https://github.com/spring-projects/spring-security/blob/f82e15d5b65734c64856ec955e82f689bf18fe1f/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/RelyingPartyRegistrationPlaceholderResolvers.java#L84
Context
We have a use case where we are helping customers troubleshoot their single sign-on configurations. Due to the nature where we need to offload incoming traffic to our load balancers on multiple domain hosts, we have to go through a whole lot of configurations which could be easily swapped out with the availability to provide our own custom URL template variables in this class.
This includes issues where the web applications are hosted in different context paths on the instances. There is currently no real way to include different context paths in the {baseUrl} templates.
If we can expose a setter method that lets the users set their own custom map of URL template variables for use, that would be great!
